bindings: Reduce the size of serialized_script_value.h

serialized_script_value.h is used in 2,000+ compilation units, and this
CL reduces its pre-processed size from 5.11MB to 1.79MB.

Also, this CL removes unnecessary #includes for
serialzied_script_value.h.

Bug: 242216
Change-Id: I8bbd09c96461d658770abe40df782d37871d3847
Reviewed-on: https://chromium-review.googlesource.com/1116410
Reviewed-by: Hitoshi Yoshida <peria@chromium.org>
Reviewed-by: Yuki Shiino <yukishiino@chromium.org>
Commit-Queue: Kent Tamura <tkent@chromium.org>
Cr-Commit-Position: refs/heads/master@{#571051}
9 files changed